Carrier phase shifting is one of the most effective methods for high-frequency vibration suppression of multiphase motors. However

there is a problem that the three-level multiphase motor system neutral line current increases abnormally after applying the carrier phase shifting. In this paper

the high-frequency vibration suppression mechanism of the fifteen-phase motor carrier phase shift is revealed by the analytical modeling of motor magnetomotive force. Secondly

combined with the modulation strategy of the inverter

the variation rule of neutral line to ground potential of three-level inverter is clarified. Thirdly

the reason for the abnormal surge in neutral line current caused by carrier phase shifting in multi-phase inverters has been identified

and a method for suppressing neutral line circulation by sequentially shifting the carrier phase of each phase within the inverter channels is proposed. Finally

the simulation model and test platform of three-level fifteen-phase motor system are built

and the neutral line to ground potential variation rule and neutral line current suppression method studied in this paper are simulated and verified by experiments. The results show good agreement between theoretical analysis

simulations

and experimental results

validating the effectiveness of the proposed neutral line current suppression method. The research in this paper can provide a solution for neutral-line current suppression method in three-level multiphase motor systems.